Is there a way to add additional social icons to the social bar at the top of the site?

Currently I have Facebook, Google+, and Angie's List (simply put it in place of LinkedIn), along with the RSS feed. My client is looking at adding a few more because there are other social media sites they have to sign up for with another service they are looking into using for marketing. I know Yelp is one of the other sites they will be wanting, but not sure of the rest.

Is there some way that I can adjust the code to be able to add more icons beyond the 4 provided in the theme settings? Or could there be something added to the theme itself that would allow additional icons to be added if desired?